Honing head



Jan. 7, 1964 c. w. vEKovlUs ETAL 3,116,573

HONING HEAD Filed Aug. 22, 1960 o a 4. 5. 5 1||I` I I I l I II| I l| N R6 f j M M w www M m E w .w 1mm La A 6 G. 8 .M .M .Y n W G f M z ,JMW I l 2 m .u a w e o 4 .n 40.. w 4 4 /v4. ...4 az f f ...MMVI |.w.| lMLIIN I I |J||I| IFI. P I I. l, I IIL II O O .fda O O O |..I|| \O N Q e I k United States Patent Office 3,116,573 Patented Jan. 7, 1964 3,116,573 HONING HEAD Charles W. Vekovius, Corunna, and Manly A. Magsig,

Owosso, Mich., assignors to Mid-West Abrasive Company, Owosso, Mich., a corporation of Delaware Filed Aug. 22, 1960, Ser. No. 51,115 Claims. (Cl. 51-184.3)

This invention relates generally to honing tools of the type having a hone body and abrad-ing elements proecting from slots -therein for the surface abrasion of a workpiece.

One object of the invention is to provide an improved honing tool of the general type refenred to which overcomes certain objections to prior tools wherein the sides Orf the `tool body slots, especially the rear sides thereof, were subjected to a high rate of wear requiring frequent replacement of the entire hone body at considerable expense.

Another object of the invention is to provide a honing tool having replaceable wear strips on the hone body in position to be engaged by and to guide the abrading elements during operation of the tool and during adjusting of the abrading elements in the slots.

Another object is to provide a honing tool wherein the wear strips are disposed between the slots and the opposite sides thereof extend ush with and in continuation of the sides of the adjacent slots.

Another object is lto provide a honing tool wherein the wear strips are symmetrical with respect to a transverse plane midway of :their length and removable to permit end-for-end reversal to present a different side to the rear or trailing face of an abrading element.

Another object is to provide a honing ftool wherein the wear strips may be replaced by other wear strips of greater or lesser radial dimension for honing holes of varying diameter.

Other objects and advantages of the invention will become apparent as the following vdescription proceeds, especially when considered with the accompanying drawing wherein:

FIGURE 1 is an elevational view, partly broken away and in section, showing a hon-ing tool embodying the invention.

FIGURE 2 is an end view of the honing tool shown in FIGURE l, with parts omitted for clarity.

FIGURE 3 is an elevational view of an expansion plate which forms a part of the honing tool.

FIGURE 4 is an elevational view of a wear strip.

FIGURE 5 is an end view of the wear strip.

FIGURE 6 is a view looking in the direction of the arrow 6 in FIGURE 1.

Referring now more particularly to the drawing, the honing tool or head is generally indicated at 10 and comprises an elongated hone body 12 which has a plurality of circumferentially spaced, elongated slots 14 in the outer surface of the body extending lengthwise thereof. The slots :are spaced apart equal angular distances and are parallel to the axis of rotation of the hone body. The slots are identical and the opposite side walls 1-6 and 18 of each slot are parallel to each other and to a radial plane through the axis of rotation of the body and through the center of the slot.

An elongated honing element 2-0 is mounted in each slot, the honing elements having been omitted from certain slots in FIGURE 2 for purposes of clarity. Each honing element comprises an elongated channebshaped holder 22 and an elongated abrasive stick 24 permanent-1y secured to the holder. The stick is T-shaped in cross section having -its narnow portion fitting within the channel of the holder and its broad portion `extending beyond the channel. The router surfaces of the legs of each channel are parallel and have a close sliding fit in the slot, and the opposite sides of the stick are also parallel and flush with and extend in continuation of the outer sides of the channel to likewise have a close sliding t in the slot.

Also in each slot is an elongated expansion plate 26 which has a close sliding t in the slot. The expansion plates have spaced recesses 28 in their radially outer sui'- faces for receiving the radial dowels 30 which project radially inwardly from the inner face of the holders to prevent the abrasive elements from moving with respect to the expansion plates. Each Iholder' `22 has the end extensions 3-2, and garter springs 34 wrap about the extensions at each end to urge the abrasive elements radially inwardly to a collapsed position and at the same time to retain the dowels 30 in the recesses 28 of the expansion plates.

The hone body is hollow or tubular, and an expansion cone 36 extends within the hone body having the cones 38 thereon in position to engage the cam surfaces 40 on the back face of each expansion plate. Downward movement of the expansion cone will accordingly shift the abrasive elements radially outwardly to expand the head, and movement in the opposite direction permits the abrasive elements to 4move radially inwardly under the iniluence 'of the springs 34 to collapse the head. Any suitable means may be provided for longitudinally moving the expansion cone relative to the hone body, Iand the hone body has at its upper end an integral formation 42 for connection with a `suitable drive to rotate and axially reciprocate the body.

Present day honing tools of this type are open to the objection that the sides of the slots are subjected to a high rate of wear requiring frequent replacement of the entire hone body at considerable expense. The slots closely conne the abrasive elements to guide their in and out movements, and accordingly the sides of the slots are abraded by the sides of the stick. Also, the trailing or rear side of each slot, particularly at its outer edge, is subject to severe wear by reason of the fact that it carries a heavier load than the front side of the slot. Assuming clockwise rotation of the head, the sides 16 are the trailing sides.

Accordingly, we provide hardened wear strips 46 between the slots which are removably secured to the hone body by screws 48. Dowels 50 extend through aligned holes in the wear strips and in the hone body to accurately position the wear strips. The wear strips are elongated and extend for the full length of the abrasive elements. The opposite sides 51 of each wear strip are formed to extend iush with and in parallel continuation of the adjacent sides of the slots on either side thereof so that they in efect form extensions of the slots and provide hardened surfaces engaged by the abrasive stick to take up most of the wear.

As seen in FIGURE 2, the radially outer surfaces of the wear strips cooperate to define a cylinder interrupted by the slots and beyond which the sticks are adapted to project for the surface abrasion of a cylinder. The outer edge of each slot on the rear or trailing side will be seen to be formed by the Wear strip and it will be seen further that in operation, the radial adjustment of the abrasive elements takes place in an area in which the sticks engage the Wear strips and do not engage the hone body. Since it is the trailing side of the slot or wear strip which is subjected to the heavier load and hence wears faster, the wear strips may after a periad of use be reversed end for end to present the opposite side thereof to the trailing side of the abrasive elements. End for end reversal is possible because the wear strips are symmetrical with respect to a transverse plane midway of their length. The wear strips are preferably made of a hardened steel for longer life. However, when they wear to the extent that too much a looseness exists between the slots and the abrasive elements, the wear strips may simply be removed and replaced by other wear strips. This is comparatively inexpensive when it is considered that heretofore the entire hone body had to be replaced.

It is also possible to replace the wear strips with other Wear strips which are radially thicker, as seen in dotted lines in FIGURE 5, and have correspondingly extended Opposite sides. Such a construction would enable the operation of the hone in abrading cylinders of larger diameter. Obviously also, wear strips which are thinner in a radial dimension and have correspondingly reduced opposite sides may be substituted for cylinder bores of smaller diameter.

What we claim as our invention is:

1. In a honing tool having an elongated hone body provided with a plurality of circumferentially spaced, elongated generally parallel slots in the outer surface of said body extending generally lengthwise thereof, and an elongated honing element in each slot, said honing elements being radially adjustable to project beyond said outer surface of the hone body for surface abrasion of a workpiece, elongated wear strips of a hard, wear-resistant material and means for removably securing said respective wear strips on said outer surface of the hone body between said slots, each wear strip having a width equal to the distance between the slots on opposite sides thereof, the opposite sides of each wear strip being disposed substantially flush with and extending radially outward from the hone body in parallel continuation of the adjacent sides of the slots on opposite sides thereof in position to be engaged by the honing elements in said slots during a honing operation and to guide the honing elements during radial adjustment.

2. The structure dened in claim 1 wherein said wear strips are symmetrical with respect to a transverse plane midway of their length so that a wear strip can be reversed end-for-end and mounted on said outer surface of the hone body is reversed position, the sides of a reversed wear strip bearing the same relationship to the slots as aforesaid.

3. 1n a honing tool having an elongated hone body provided with a plurality of circumferentially spaced, elongated generally parallel slots in the outer surface of said body extending generally lengthwise thereof, and an elongated honing element in each slot, said honing elements being radially adjustable to project beyond said outer surface of the hone body for surface abrasion of a workpiece, elongated wear strips of a hard, wear-resistant material, and means for removably securing said respective wear strips on said outer surface of the hone body between said slots, each Wear strip having a width equal to the distance between the slots on opposite sides thereof, the opposite sides of each wear strip being disposed substantially flush with and extending radially outward from the hone body in parallel continuation of the adjacent sides of the slots on opposite sides thereof in position to be engaged by the honing elements in said slots during a honing operation and to guide the honing elements during radial adjustment, said wear strips having arcuate outer surfaces of the same radius which cooperate to define a cylinder interrupted by said slots, said means for removably mounting said wear strips on said hone body permitting removal and replacement thereof with wear strips having radially extended or reduced sides and arcuate outer surfaces of correspondingly greater or lesser radius, said wear strips being symmetrical with respect to a tranverse plane midway of their length so that a wear strip can be reversed end-for-end and mounted on said outer surface of the hone body in reversed position, the sides of a reversed wear strip bearing the same relationship to the slots as aforesaid.

4. A wear strip adapted to be removably secured to the outer surface of a honing tool body between circumferentially spaced, elongated radial slots in said outer surface of the body which extend generally lengthwise of the body and each of which have parallel sides to receive honing elements therein adjustable inwardly and outwardly to project beyond said outer surface of the hone body to abrade a workpiece, said wear strip being in the form of an elongated member having straight ilat sides which extend from the opposite edges of the outer surface of said member in converging relation and at substantially the same angle thereto so as to extend flush with and in continuation of the adjacent sides of the slots on either side of said member when the latter is removably secured to said outer surface of the hone body as aforesaid, said elongated member being of uniform cross-sectional outline throughout its full length.

5. The wear strip defined in claim 4 wherein the outer surface of said elongated member is arcuate.

References Cited in the le of this patent UNITED STATES PATENTS 1,673,924 Snyder June 19, 1928 2,304,930 Klein Dec. 15, 1942 2,330,184 Hause Sept. 21, 1943 2,751,726 Klein June 26, 1956 2,777,257 Johnson Jan. 15, 1957 2,823,498 Saunders Feb. 18, 1958 2,998,681 Calvert Sept. 5, 1961 3,064,397 Czubak Nov. 20, 1962 

1. IN A HONING TOOL HAVING AN ELONGATED HONE BODY PROVIDED WITH A PLURALITY OF CIRCUMFERENTIALLY SPACED, ELONGATED GENERALLY PARALLEL SLOTS IN THE OUTER SURFACE OF SAID BODY EXTENDING GENERALLY LENGTHWISE THEREOF, AND AN ELONGATED GENERALLY PARALLEL SLOTS IN THE OUTER SURFACE OF SAID BODY EXTENDING GENERALLY LENGTHWISE THEREOF, AND AN ELONGATED HONING ELEMENT IN EACH SLOT, SAID HONING ELEMENTS BEING RADIALLY ADJUSTABLE TO PROJECT BEYOND SAID OUTER SURFACE OF THE HONE BODY FOR SURFACE ABRASION OF A WORKPIECE, ELONGATED WEAR STRIPS OF A HARD, WEAR-RESISTANT MATERIAL AND MEANS FOR REMOVABLY SECURING SAID RESPECTIVE WEAR STRIPS ON SAID OUTER SURFACE OF THE HONE BODY BETWEEN SAID SLOTS, EACH WEAR STRIP HAVING A WIDTH EQUAL TO THE DISTANCE BETWEEN THE SLOTS ON OPPOSITE SIDES THEREOF, THE OPPOSITE SIDES OF EACH WEAR STRIP BEING DISPOSED SUBSTANTIALLY FLUSH WITH AND EXTENDING RADIALLY OUTWARD FROM THE HOME BODY IN PARALLEL CONTINUATION OF THE ADJACENT SIDES OF THE SLOTS ON OPPOSITE SIDES THEREOF IN POSITION TO BE ENGAGED BY THE HONING ELEMENTS IN SAID SLOTS DURING A HONING OPERATION AND TO GUIDE THE HONING ELEMENTS DURING RAIDIAL ADJUSTMENT. 